In high-frequency surgery (HF surgery) an electrode supplied with high-frequency electric current is used for sectioning tissue. A high-frequency electrode made of a wire sling is used, for instance, for detaching tissue. The sling is pushed or pulled through the tissue by the operator in order to cut out snippets or shavings of tissue of just about any length.
A medical resector as set forth in the following description can be combined with an endoscope to form a resectoscope, in such a way that a shaft of the endoscope is positioned inside a channel in the shaft of the medical resector.
A medical resector developed by Jacques Hamou comprises a rotating wire sling as high-frequency electrode. The wire sling ablates the tissue in the form of small shavings or snippets, for instance similarly to the functioning of a milling head for machined processing of workpieces. Medical resectors of this type are described for instance in WO 2006/048199 A1 and DE 10 2006 039 696 A1. Resection or ablation or the detaching of tissue in small fragments makes possible an immediate visual control, simplified handling, and clean and precise ablation of tissue. In addition, the small portions of tissue are easily removable, for instance by suction integrated in the medical resector.
As with all instruments used for microinvasive medical interventions, the smallest possible shaft diameter is also desirable for a medical resector. The shaft of a medical resector as a rule comprises a channel for inserting the shaft of an endoscope. The ablation of tissue can be directly observed through the endoscope by means of the medical resector. In addition, the shaft of a medical resector with a rotatable high-frequency electrode comprises an axle for transmitting the rotation motion from a drive mechanism to the rotatable high-frequency electrode. As a result of the smallest possible cross-section of the shaft of the medical resector, the axle is situated close to the endoscope or to the channel for the endoscope. In addition, the rotatable HF electrode should not extend above the contour of the shaft of the medical resector, in order to make possible, for example, the insertion by means of a trocar. To make it possible, with the given diameter of the shaft of the medical resector, to simultaneously have a maximum diameter of the HF electrode, the axle must be located as close as possible to the symmetrical axis of the shaft. However, this leads to geometric problems at the proximal end in coupling the medical resector and a drive mechanism for rotating the rotatable HF electrode.
Additional problems with conventional medical resectors with rotatable HF electrodes are the irrigation of the work area and the removal of severed pieces of tissue from said work area. Irrigation and the removal of severed tissue pieces are necessary to ensure a clear view of the work area, for example through the aforementioned endoscope.
Other problems that are often not resolved, or not sufficiently resolved, with conventional medical resectors with rotatable HF electrode are the protection of patients from injury from the rotatable HF electrode and the protection of a rotatable HF electrode from damage, in particular during insertion and positioning of the medical resector in the work area in a cavity in the patient's body.
It is an object of the present invention to create an improved medical resector.